This article talks about  some basic rules for runner design of plastic toolings, which, if you follow, will help you succeed with an injection mold design.  To provide part-to-part uniformity in a multicavity mold, the runner system should enable each cavity to fill at the same rate. Designing runners involves several compromises: The runner system should be compact to minimize the amount of rework. The runners must deliver melt that has retained maximum heat to completely pack out the cavity. At the same time, runners must cool quickly after delivering the melt to aid ejection. If the flow distances from the sprue to the various cavities are equal, the runner system is balanced. Since balanced runner systems contribute to melt uniformity among cavities, dimensional tolerances are easier to maintain. Unbalanced systems can cause cavity to cavity variations. (Figure 1) Figure 1 Occasionally, balancing the runner system and minimizing runner length conflict. In most cases it is better to accept the additional rework and use a more balanced system. Increased injection…

More and more China mold makers are involved in manufacturing plastic injection molds for Engine Coolant Recovery Tank Mount . However, the warp issue caused by plastic PA66＋30GF is always a big challenge to overcome. To handle the injection tooling project of  Radiator Expansion Tank Mounting Plate, it requires consolidating force from each team including mold flow/design/machining/QC. And the whole team must own rich experience, otherwise the critical dimensions are difficult to be achieved and mold has been changed again and again. For most companies, core and cavity needs to be replaced at least one time. Dumping away blocks is quite commonly seen. Mold Flow． Use Mold flow to calculate the warp and gate location with the size normally between4－6mm. Now here is the question, a lot of mold makers complaint about that the result from Mold flow differs greatly with actual result. According to our years of experience, mold flow reading is feasible, but…

Cold slug well is a very imporant part of plastic mold design. It is  defined as the small nub of plastic that cools and solidifies inside the nozzle tip during the cooling cooling phase of the injection cycle. It is designed to store cold slug  caused intermittently by the nozzle due to heat loss and low temperature. Cold slugs could clog or slow down the material flow in runner and cavity and cause cold scars or cold marks on plastic part. The cold slug well is usually placed at the end of primary runner. When the branch runner is too long, cold slug well should be designed as well to store the front plastic cooled by mold. Cold slug well is a very imporant part of gate system and it should not be neglected at mold design.   For molded plastic part made from flame-retardant PC, the design of cold well determines the the quality of…

Product name Plastic blower fan for power driven machine Product Material Engineering PP Injection molding machine 300 T Process Injection molding Runner Cold Sprue Cavity 1X1 This is a cold sprue injection mold for power-driven machine and the material is engineering plastic PP which is high temperature resistant. It is a thick wall plastic injection molded part. Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more.  HS MOLD is a manufacturer of thermoplastic injection molding services including new product development,…

Product name Injection Molding Plastic Parts Product Material PP+30%GF Injection molding machine 480T Process Injection molding Runner Hot sprue Cavity 1X1 This is a hot runner injection mold for  injection molding plastic parts and the material plastic is PP+30%GF. A1 polishing finish on the surface. Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more.  HS MOLD is a manufacturer of thermoplastic injection molding services including plastics engineering and design, custom injection molding, final product assembly, mold making, and prototype development.

Silver streaks are a very common phenomenon appearing on the surface of plastic injection molded products. They are shining line shaped patterns usually caused by moisture, but can also be caused by high filling rates and poor vents which can cause entrapping of gas either from the environment, mold water leaks, etc. These can be considered external appearance quality defects in exterior parts of consumer electrical products, automobiles, motorcycles, etc. The most commonly seen streaks are shown as below. Moisture streaks/splay marks Burning streaks/silver streaks   Dark streaks Color streaks     The cause for the formation of streaks can be deter-mined in many defective injection products only after costly investigations,especially as the appearance of burning and moisture streaks is similar.Extensive knowledge of the plastic,the mold design and the plastic injection molding processing are indispensable for overcoming the problem.Before launching expen-sive and time-consuming investigations the following points should be checked in the sequence given and if…

Product name Plastic motorcycle accessories Product Material PC Injection molding machine 480T Process Injection molding Runner Cold sprue Cavity 1X1 This is a hot runner injection mold for auto parts and the material plastic is ABS+30%GF. AND No black spots on the surface and no blinster！ Our factory is equipped with various size of injection machine ranging in tonnage from 55 tons to 610 tons and shot capacities ranging from 1.3 oz to 80 oz. We can meet any of your custom injection molding needs using different types of plastics including ABS, PC, PP, Nylong and so on. We produce custom injection molded finished products and parts for direct shipment to oversea end customers  We produce standard and custom plastic products for various industries including Automotive, House hold application, Medical and more. Since 2005, HS Mold has specialized in custom, high-volume plastic injection molding. Our team are committed to the success of your project and works hard to meet or…

Stack Mold Technology & Application This article mainly decribes about Stack Mold Technology & Application in plastic injection molding. What is Stack mold? Stack mold can be described as a mold assembly consisting of a series of single-face molds of the same size, mounted back-to-back or “stacked” next to the other. Without increasing the plastic injection molding machine platen size or tonnage, stack molds double (or more for increased stack mold levels) the output of standard plastic injection molds, increasing molding efficiency and reducing the overall part cost. Stack molds can also produce multi-component assemblies or a family of parts in one shot on one plastic injection molding machine. Most stack molds have an equal number of the same cavities in each side of the mold, or parting surface, but they can also have different cavities in each mold parting surface to produce a family of parts per shot, with each part being a different…

This article discusses basic consideration for designing two-shot injection molds, which is referred to also as dual-shot, dual-injection, double-shot, double-injection, multi-shot, 2k molding, and overmolding Before tool design, one should check machine injection unit Injection unit sometimes constrain the tooling type. Material shrinkages for each material should be considered. Shrinkage may cause warpage and flash if those are not made up properly in tooling phase. If there is big different in melt temperature between materials, toolheat balancing should be .studied Tooling should consider gate location, access, allowable gate vestige. Draft angle in 2K molding is very critical factor which deciding wheremolded part stuck and rotating. In 1st shot molding, molded part should be stuck on rotating core and 2nd shot molding, molded part should remain on the side of ejecting system employed.   If part design imposing creating shut-off surface with molded part after rotating,Draft angle on shut-off surface should be…

In this article, we will show you from three aspects to be taken into consideration when designing plastic parts for double injection molding so we can save our customers time and money in the long run.   Mechanical structure     Surface Contact Adhesion is depending on materials compatibility, process temperatures, surface contact area, molding sequence and designing of mechanical interlock systems. If design not allows enough contact surface area, Tooling can make up like Make-up 1 : Increase expose surface byincreasingroughness. Make-up 2 : Employ interlock Wall Thickness Utilize 2nd shot to get more uniform wallthickness  Reinforce the 1st  and 2nd shot(transparent) by structure design such as “H” section etc. Thin but high rib in 2nd short. First shot thicker than 2nd shot. 2nd shot should be as thin as possiblewhen flow and weld line is not a issue. In MP case, 1st shot 0.6mm, 2nd shot 0.6mm was made Avoid sharpcorner Make…